Using --password fails if ~/.config/x11docker doesn't exist

[echuber2]

Fixed by #535

If $HOME/.config/x11docker doesn't already exist, among other possibilities, --password fails because of some logic errors in the code that sets the password. See #535 for details.

To reproduce:

1. Remove directory $HOME/.config/x11docker
2. Run: ./x11docker --password

Results:

$ ./x11docker --password
Please type in a new container user password (chars are invisible): 
./x11docker: line 11356: mkdir -p  '/home/[user]/.config/x11docker': No such file or directory
chmod: cannot access '/home/[user]/.config/x11docker': No such file or directory
./x11docker: line 1913: /home/[user]/.config/x11docker/passwd: No such file or directory
chmod: cannot access '/home/[user]/.config/x11docker/passwd': No such file or directory